Food and industrial Microbiology

Question 1

what causes food spoilage

Answer 1

food spoilage is primary related to high water content (aw)
also different types of foods have different organisms which attack them

Question 2

how to prevent spoilage

Answer 2

effect abiotic peramiters which the bacteria need to thrive such as pH, temp, water activity

Question 3

Canning

Answer 3

A process by which food in sealed and then heated to kill all living organisms in the process
spores will still be present in the food so stirring while heating is key

Question 4

chemical food preservation

Answer 4

use of chemicals such as sodium propionate, nitrates and antibiotics

Question 5

*state and describe 3 abotic parameters that can be manipulated to contorl microbial growth in foods

Answer 5

pH
temperature
water activity

Question 6

what are the advantages of using plasmids as cloning vectors

Answer 6

1) small size
2) stability of circular DNA
3) independent origin of replication
4) multiple copy numbers so DNA amp is possible
5) contains selectable markers

Question 7

what are some practical applications of Genetic engineering

Answer 7

1) Microbial fermentations (increased yields of product via genetic manipulation)
2)virus vaccines
3)mammalian proteins–again commercial production of human proteins(insulin)
4) transgenic plants and animals (increased crop yields and more meat on animals) (however more susptible to disease)
5)envoirmental biotech(biodegration of toxic materials)
6)gene regulation and gene therapy (designer drugs)
7)bioleaching
8)oil recovery

Question 8

*ice nucleation

Answer 8

done by psedomonas syringae
the bacterium possesses an ice nucleating gene that gives it the ability to catalyze the freezing of water when near freezing tempatures this can reslut in increased frost damage to crops

they have used the the ice- gene which does not super cool the water thus protects the crops form bacteria with the ice + gene which super cools